# CVE-2025-21883: ice: Fix deinitializing VF in error path

> A use-after-free in the Linux kernel ice driver can cause a system crash when configuring SR-IOV VFs in switchdev mode.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 27 Mar 2025
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2025-21883, DEBIAN-CVE-2025-21883, GHSA-957j-8wc9-pfwx, ROOT-OS-UBUNTU-2404-CVE-2025-21883, UBUNTU-CVE-2025-21883

## What is CVE-2025-21883?

CVE-2025-21883 is a high-severity use after free vulnerability in Linux kernel, published on 27 Mar 2025. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

ice: Fix deinitializing VF in error path

If ice_ena_vfs() fails after calling ice_create_vf_entries(), it frees
all VFs without removing them from snapshot PF-VF mailbox list, leading
to list corruption.

Reproducer:
  devlink dev eswitch set $PF1_PCI mode switchdev
  ip l s $PF1 up
  ip l s $PF1 promisc on
  sleep 1
  echo 1 > /sys/class/net/$PF1/device/sriov_numvfs
  sleep 1
  echo 1 > /sys/class/net/$PF1/device/sriov_numvfs

Trace (minimized):
  list_add corruption. next->prev should be prev (ffff8882e241c6f0), but was 0000000000000000. (next=ffff888455da1330).
  kernel BUG at lib/list_debug.c:29!
  RIP: 0010:__list_add_valid_or_report+0xa6/0x100
   ice_mbx_init_vf_info+0xa7/0x180 [ice]
   ice_initialize_vf_entry+0x1fa/0x250 [ice]
   ice_sriov_configure+0x8d7/0x1520 [ice]
   ? __percpu_ref_switch_mode+0x1b1/0x5d0
   ? __pfx_ice_sriov_configure+0x10/0x10 [ice]

Sometimes a KASAN report can be seen instead with a similar stack trace:
  BUG: KASAN: use-after-free in __list_add_valid_or_report+0xf1/0x100

VFs are added to this list in ice_mbx_init_vf_info(), but only removed
in ice_free_vfs(). Move the removing to ice_free_vf_entries(), which is
also being called in other places where VFs are being removed (including
ice_free_vfs() itself).

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2025-21883?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2025-21883?

Apply the vendor's patch.

## Is CVE-2025-21883 being exploited?

There is no known exploitation of CVE-2025-21883 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-21883 and fix it if it is affected.

What it is: CVE-2025-21883 is a high-severity use after free vulnerability in Linux kernel, published on 27 Mar 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2025-21883 in the wild and no public exploit code.

Affected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2025-21883/ (Markdown: https://insights.sbomify.com/CVE-2025-21883/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-21883
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-21883
- OSV: https://osv.dev/vulnerability/CVE-2025-21883

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-21883/
Summaries are generated and may contain mistakes; the official description above is the record.